This invention relates to a multichannel tone signal generation device having individually and uniquely addressed channels and which is capable of generating a tone signal having a tone color controlled in accordance with tone color change control information such as key touch.
For generating a tone having a tone color controlled in accordance with key touch, it has been proposed to read out plural different waveshapes from a waveshape memory and interpose and synthesize these waveshapes at a ratio corresponding to the key touch (U.S. Pat. No. 4,231,276). In this case, waveshapes to be interpolated are not necessarily two channels but it is desirable to use more channels because a more complex tone color change control and hence a closer simulation of a desired tone color can thereby be realized. In the above mentioned U.S. Patent, for example, different waveshapes are generated in three channels, coefficient parameters are independently generated for respective channels and ratio of synthesis of waveshapes of corresponding coefficients is determined independently by these coefficient parameters.
In the above described prior art device, channels for the interpolation operation are provided in one-to-one correspondence for all waveshapes which are subjected to interpolation and, accordingly, multipliers for the interpolation operation and interpolation coefficient generation circuits of the same number as the waveshapes to be interpolated are required and this results in bulkiness in the circuit design.